GPT Disk Identify and Fix

Just curious if anyone knows why Microsoft didn't allow for Windows 7 to be installed on a disk formatted GPT. My system has 4 750GB drives in Raid 5, with "2 disks"... Disk 0 is about 48GB (with less than 10GB free) and has Vista Ultimate x64 installed (obviously formatted MBR), and Disk 1 is about 2TB (formatted GPT) with a whole bunch of media. I didn't plan to be dual booting, or I would have created Disk 0 to be a little larger. I must be "new" as I thought I would have been able to just shrink my 2TB disk and move some space over to the MBR disk, but after doing a shrink I can't do anything with the extra space besides make a new simple volume on the GPT disk. Am I stuck? Why in the world would Microsoft not support installing on a GPT disk by now? I was pretty upset as it was when I couldn't just create one large volume to install Vista on when I built the machine.

When a GPT Disk is re-sized, the private region does not need to move and so there is no header update. When a volume is re-sized, this gets written into the private region - again, does not require a header update. When a rescan is initiated, the header is read from the disk and loaded into memory. As the header contains the old public region size, the disk appears to revert to its former size. The expanded volume is now bigger than the public region and the volume will go missing as it is smaller than its contents.

This fix specifically addresses the problem identified above. It has not been fully tested and should be applied in a test environment before placing into production. If the systems are not critically impaired, it is recommended to delay the installation of this private fix until the next scheduled maintenance release. Before applying this private fix, systems may be required to be upgraded to the latest code base. The support representative will help in determining the best course of action.